Joint for concrete slabs



Oct. 5, 1937. E. H. GEYER l y 2,095,061

JOINT FOR CONCRETE SLABS l Filed March 16, 193e Patented Oct. 5, 1937 s.

, UNITEUSTATES PATENT ori-*ICE ErnestH. Geyer,v Chicago, Ill., assigner' of onel half to Henry A. Taubensee, Chicago, Ill.

Application March 16, 1936seria1No. 69,026

11'o1aims.. (o1. 94-18) ,fIhe present invention .relates generally to joints for concrete. More particularly the in- Ivention relates to that type of joint'which is adapted foruse between a pair of adjoining or 5 contiguousr slabs in a roadway or` like concrete construction, operates as a load-*transfer unit and at 'the same timepermits of Vvexpansion and contractionof the slabs .and comprises (1V) a pair of laterally spaced load distributing bars `which are adapted for association respectively with the adjoining portions of the slabs and to extend transversely through the slabs; (2) a plurality .of dowel rods which extend betweenand at right angles to the load distributing bars and extend through the meeting faces of the slabs; and (3) a set'of sleeves whichve'ncase and are slidable relatively to the vrods and are adapted to become bonded to the concrete. l

' One object of the inventionl is to provide a joint of this typewhich is an improvement uponv and certainadvantages overithat kwhich is-illustrated in andr forms the subject matter of my copending rapplication forUnited `States Letters Patent, filed November 1, 1935, Serial No. 47,7341.`

'Another object of the invention is toprovide a joint ofthe type under consideration in which the endsV of the sleevesvhave notches for retaining the, load distributing bars `and also have caps which serve as closuresv for preventing the` o0 'inow of vconcrete during pouring of the slabs.

vA furtherobject ofthe invention is to provide a concrete joint of the aforerrientioned type and character which embodies simple and improved means for Aexcluding concrete or iiller fromrthe slots which serve to weaken the central `portions of the sleeves in order lthat the end portions are readilyrnovable to and from onelanother in response to expansion and contraction of the slabs A still further object 'of theinvention is to 40 provide av concrete joint which is generally of n new and improvedy construction, may be manufactured Vat a low and reasonable cost, and is so designed and constructedlfthat it may be assembled quickly and readily and will not crack orbreak the concreteslabs withwhich it is used. t

Other objects ofthe invention and the various advantages and characteristics of the present 'joint will be apparentffromia consideration of the following detailed description.r

,30 The invention consists in the severalnovel feav tures which are hereinafter Aset forth `and are more particularly defined by claims at the conclusion hereof.

.In the'drawing which accompanies-and forms y a part of this specification or disclosure and in which like numerals of reference denote corre-` sponding parts throughout the several viewsiz" l Figure 1 is a horizontal sectional view of `two adjoining slabs of concrete having therebetween a joint embodying the invention; f 5 Figure -2 is `an enlarged vertical longitudinal section through one of thesleeves of the joint; Figure -3 isa vertical transverse `section taken on the line 3--3 of Figure 2 and showing in "detail` the slot arrangement whereby the central 10 portions of the sleeves arelweakened so that the end parts of the sleevesv are movable to and lfrom one another and slidable with respect to the dowel rods in response to expansion or contractiongof the slabs; t Figure 4 is a detail perspective View showing the manner in which the'ends of the sleeves are notched in order to receive and retain the load distributing bars; 1' Lk Figure 5 isv aperspective of one of the caps 20 which t'over the notched ends` of fthe sleeves and form closures for preventingv the'inflow oi"y concrete during 'pouring of theslabs;

' lFigure 6 is a vertical sectionlof a joint embed-yfy ing a modified form Aof the invention; l25v n vFigure '7 is a vertical transversesection on the line Y'l.-'l of Figure 6; i f

Figure8 is adetail perspective view showing the bar receiving notchi `formation 'at the' jends of the sleeves of the joint'of Fgure; and 30 Figure 9 is a perspective of one of the caps which is used as anend closure for the sleevesof the Figure 6 joint.

The joint which is'shown in Figures 1, 2,8,"4' j and 5 lof the drawing constitutes the preferredl35 mits the slabsv III and II of the-roadwayY to ex:- `#i5 f pand land. contract as `the result of changes in temperature or climatic conditions. Itv is of unitary design or construction and consists 'of a pair of laterally spaced, horizontally extending;

loadvdistrlbuting bars -I4 and I5, a set of sleevesl 50 I6 between the'bars I4 and I 5 and a plurality'oi dowel rods Il in thesleeves. The load distribut` ing bars I4Y and. I5 are associated respectively withthe slabs I0 and II and extend transversely through the latter, as shown in Figures 1 and 2. `'55 2' 1 l e 9,095,061 vPreferably the distributing bars i4 and I5 are located midway between the top and bottom faces of the slabs and are positioned from the kfiller Il a distance corresponding substantially to the thickness of the slabs.

TheQsleeves liextendbetween and at right t angles to the loadk distributing bars I4 and i5 and project through the resilient 1111erv I3.- They formed oi' any suitable type of metal and are. oi' uniformy diameter throughout.

'l'he outer Y faces of the sleevesare coatedmwith zinc or any other lmaterial which when brought intol contact with concrete 4bonds itself to thel concrete as the result of the chemical action which takes place. Because of these coatings the end` portions of the sleeves at one side of the filler I3 become bonded to the concrete of the slab i0 and the other end portions of the sleeves, that isy the end portions at theother side of the fliier Il become bonded to the concrete of 'the slab Il. 'Ihe load'distributing bar i4 inthe slab lil fits l within notches i0 in the contiguous endportions ofthe sleeves I6 and is heldin lplace or connected relation withrespe'ct to the sleevesfby meansof 25 caps jiS. 'I'he notches It extend inwardly' from theouter edges ofthev sleeve Vend portions that arev in the -slab `Iii and have rounded inner ends which] are shaped conformably ,and correspondv in diameter .to the I4.l .The-outer ends of the notches are lflared `to permit of ready entry f ofthe bar i4and the central or intermediate portions of the notches vrare narrower thanthe ared i outer ends and the 'rounded inner ends with the result that the bar i4 whenyin place inthe-inner *ett n 4 ends of the notches isheld in place.

i necting the'bar I4 to the sleeveitis merely moved 1 sidewise into the notchesvuntil itis snapped in place in the inner ends ofthe notches. The caps il serve as end closures for the sleeve end' portions havingzithe notchesll..` They-are V-in the kformoif metal stampings` and' embody. vcircular end .walls p20 and substantially cylindrical side wam 2|. VThe side wensnt overtnenotehedfend portionsof the sleeves, as shown in Figure 2,V and have notches 22 forreceiving -thefloadfdis tributingbar i4. The ,end walls 20 abut'against the contiguous end edges'of thesleeves, and form" closures whereby the inflow of concrete into the sleeves is prevented during pouring of the4 slab I0. e'notches 22correspond in ,shape .to the notches Il inth'e sleeves.Y as showninFigure 5.

'I'he inner endsoIjthehOtches are shaped conformably. andeorrespond` in diameter to the bar i4 and form sockets in which the bar is disposed,

(see Figure 2). 'I'he vcentral portions of the notches V22 are `Vnarrower than the inner"V and j outer ends with theA result that entry ofthe bar into'the notches is .facilitated Aand the caps snap into .positionaround the barwhen theyare driven or -slidA onto the contiguousend` portionsof the sleeves. 'I'he end portions of the sleeves in" the slabs H `have notches. 23 for receiving the'` load distributing bar l and haveecaps 241 which" vserveasend closures and prevent theinnowof 65` n vnotches 23 are similarin shape to the notches concrete during "pouring -of the slab '|i. 'Ihe il Iand have rounded inner ends in which theload distributingbar i5 is disposed. 'I'he caps 24 are the sanielindesign and construction las the caps I land have notches-25 inthe side walls thereof Y through which the,barv i5 extends.- When-the `caps I9 and 24 areinplace the ends AIof the sleeves are sealed and the'load distributing bars i4 andi 5 are secured flxedly in place. The load e distributing-bars andisieeves are preferably assembled at the place where theslabs lil andy II` are formed. -In assembling the joint the load distributing bar I4 is rst snapped into the notches I8 and then the caps I9 areapplied so as to hold the bar in place. Thereafter the bar i5 is snapped into the notches 23 and the caps 24 are applied. When the bars are in place the sleeves are heid in parallel relation.

'Ihe dowel rods i1 t snugly and slidably` inf ,the sleeves I6 and the ends thereof, as shown in Figure 2, terminate slightly inwards ofthe .rod

distributingbars` i4 audit `They constitute. the e load transfer members of the jointand are coatedl with graphite or any other suitable lubricantY prior to insertion in the sleeves so that they are slidable relatively to the latter and thus permit the end portionsof the sleeves to move to'andA from one anotherin response to contractionand expansion of the slabs iiand il. Iny order toV permit the end portions of the sleeves at one side of the iilier to move to and from the end Dortions of the sleevesmat the other side of the fillerY they central portionsof the sleevesyare weakened 1 i" l by way of Van annular v`series of\"longitudinally extending slots 28. Boy' employing the slots the centralportions of the sieevesjarefsufilciently t f weakenedV so that f they either expand or 'buckle the sleeves toward one vanother or rupture in the event that the end portions of the sleeves move contraction on thepart of the slabs I0 Yand fli..

tov installationthe.dowe1 rods are allretained in parallel relation and as airesult `thereis no i in response to "movement of the end'portinsofn By having the sleevesy of one-piece design vprior misalignment whichlwould tend to` cause either f the formation of funnelshapel sockets: inthe slabs or breakage ofthe concrete.

In order to` ex the sleeves viathe slots 26-and .also to'prevent yconcrete fromentering the central portionof elude the nner is'frem entering 40.

the sleeves yduring pouring of` the" slabs i0 and l i,

shieldsV 21 are provided. 'I'hese shields areasso-Y ciated with the central portions of the sleeves Il andeach' comprises a` ring-shaped Lsection 28 andl a complementa] ring-shaped section 29; ',.Tl'e shield sections 21 arespaced from and' extend around the slot lweakenedcentral portions of the.

sleevesY I6, as shown in Figure 2, and have in-L` turned end flanges 30 whichsurround and are welded or .otherwise rigidly secured't'o thexend f portions of the sleeves which aredi'sposedfin yand fj bonded to the slab It.' Thecomplemental ringshaped sections 29 surround and engage,"s'lidablvv f 'y .l

the sections 28 and lhave inturnediiangesli whichgare welded, soldered or otherwise flxediy g secured to the'end'portionsof the sleeves in the slabV In. rBy having the sections za and is er' l the shields connected respectively to the opposite(A end portionsoi'thesleeves the shieldsections move in telescopic relation in response to movement of the end portions ofthe sleeves to "andv` from one another asa result of the expansion'a'nd contraction of the slabs, By reasonV ofthe tele-Ef'.

scopic t between 'the sections of the shields 'the Vfiller |43 is excluded from theIslotted central por-l e tions of the sleeves and concrete cannot ow' by f way'of the slots 2s inte the interior of the sleeves during pouring of the slabs l0 and Il'.

l3`may be of any suitable material suchA as poured or. premoulded bitumen; cork or rubber which will permitofthe desired expansion and contraction e of the slabs. 'I'he shields 21,serve to exclude the s nner in the event that it is poured between the slabs. It also excludes moisture land dirt. from 30 v awayofrom one anotherv as the` result of marked t I the central portion of the sleeves after pouring of the filler. If a premoulded ller is used instead of a poured fillerl the sleeves with the shields thereon are inserted into the filler and supported thereby.- Thereafter the load distributig v bars I4 and I5 are inserted respectively into the notches I8 and 23""in the end portions of the sleeves and the capsI 9 and 24care applied. After connection of the load distributing bars to the sleeveschairs,4 supports, brackets or like devices (not shown) are set under the sleevesor load distributing barsso as to lhold them in place` during pouring of the concretein connection with the formation of `the slabs I0 and II. After the slabs have been poured the end' portions of the sleeves in the slab I8 vare free to move with the slab I0 and relatively to the end portions of the sleeves in the slab II. During expansion and contrae-,- tion of the slabs the shield sections 28 and 29 exclude moisturey and dirt from inside of the sleeves and thus prevent' the dowel rods from sticking to the sleeves. The Joint of Figures l to 5 is in thenature of an expansion joint. When a preformed 'filler is' used itis not essential to use the shields 21. The sleeves withor without the shields thereon are preferably vfabricated vat the factory and assembled with the load distributing bars I4 and I5`at theplace of installation.

'I'he joint'which is shown in Figures 6, 7, 8 and 9 is a contraction jointV and is shown in connection with apair of roadway forming concrete slabs IIland II. It consists of a pair of load distributing bars I 4a and vI 5e, a plurality of .sleeves Isl, and a plurality of dowel rods I'I, and it is similar to the joint of Figures'l'to 5 in that it serves as a load transfer unit. The bars I4* and I5* extend transversely through. and are asso-A ciated respectively with the slabs IU, and Il@ and fit lin notches 32 in the ends of the sleeves and II by means of caps 33. These caps arel preferably in the form of metal stampings and comprise circular end Walls 34 and annular or cylindrical skirts 35. The end walls 34 have diametrically opposite arcuate slots 36 through which extend the parts of the end portions of the sleeves on ropposite sides of the notches 32. As shown in Figure 6 the end' walls 34 of the vcaps are aligned with the inner ends of the notches 32 and the skirts 35 surround the adjacent parts of the sleeves. In assembling the joint thecaps 33 are first mounted on the ends of the sleeves. Thereafter the'load distributing parts I 4 ,and I5 are inserted into the notches 32 and are secured xedly in place against the end walls.34 or caps by deflecting Vor bending inwards by. way of pliers or a hammer the outer extremities of the sleeves. When the caps 34 are in place the ends of the sleeves are effectively sealed. The dowel rods I'I fit snugly in and are slidable lengthwise of the sleeves I6* and are of such length that thep ends thereof terminate slightly inwards of the end walls 34 of the caps 33. 'Ihe central portions of the sleeves are slit longitudinally as at 31 to form strip-like connecting elements or bonds 38.n

These bonds are bu1ged.outwardly,l as shown in Figures 6 and 7, and permit the endportions ofl the sleeves to move toand from one another in response to expansion and vcontraction ,of the slabs. Sheet metal shields 89 surround the central portions of the sleeves. l These shields have inwardly extending end flanges 48; which are welded or otherwise xedly secured to the portions of the sleeves which are immediately adjacent to the bonds 38. The central portions of the shields are U-shaped in cross-section so as to permit` the end parts to flex or move to and from one anothfr. The U-shaped central portions of the shields are aligned withthe crack which forms the separation point betweenl the slabs I8` and I I". By havingl the` U-shaped central portions of the sleevessoA positioned the shields although rigid with the sleeves are4 movablewith the end portions of the sleeves.l 'I'he shields serve toy exclude concrete from entering thesleevesvial the slits 3l during pouring of theslabs.- They also exclude dirt and moisture from the sleeves.

`The herein described joints Yare extremely eilicient as far as fulfllling'their..intendedfpurpose is concerned. They may be easily vassembled and` by reason of the fact that they consist of but a ysmall `number of parts maybe `fabricated at alow and reasonable cost. 1 y

The invention isnot to befunderstood as restricted to.the details set forth since these may be modified within the scope of the appended claimswithout departing from \the.. spirit and scope of the invention l, i

Having thus described the invention what I claimas new and desire to secure by letters Patent is: c i

1. In a joint for contiguous concrete slabs, the combination of a pair of laterally spaced load distributing bars adapted for. embedment In and to extend transversely through the slabs. respectively, a` plurality of .metallic onepiece sleeves between the bars adapted to have thetend portions thereof bonded respectively to the slabs and having their extreme outer ends connected Y. to the bars and the central portions thereof sleeves and, extending `across the `'central pox'-v tions thereof, and individual, expansible andv contractible Aannular shields around the central weakened portions of `the sleeves.

2. Ina joint for contiguous concrete slabs, the

combination of a pair of laterally spaced load disl tributing bars adapted for embedment in and'to extend transverselythrough the slabs respectively, a plurality of metallic one-piece sleeves be. tween the bars adapted tovhave the end portions thereof bonded reslliectively` to. the slabsgand A` having notches in their outer extremities through which the bars extend and also having weakened formations in the central portions thereof whereby the latter will readily expand or distend t or rupture and hence permit said end portions to move to and from. one another inn response to expansion and contraction of the slabs, separately formed caps mounted on and arranged to close the ends of the sleeves, and dowel rodsV mounted slidably in the sleeves and extending across the central portions thereof.

3. In a J'ointfor contiguous concrete slabs, y

the combination of a pair of laterally spaced load distributing bars adapted for embedment inand c to extend transverselythrough the slabs respectively, a plurality of metallic one-piece sleeves between the bars adapted -tto havethe end por, v

tions thereof bonded respectivelyiv to4 the slabs and having. notches in ytheir outer extremities through which the bars extend and4 alsovhaving weakened formations in theA central portions.V

thereof whereby the latteriare free to expand or distend or rupture and hence permit said end '4o j *v y(2,095,061

portions tov move'tof` and" frornl one another-in response'to expansion 'and contraction ofgthe f alaba-separately fforrned capsfmounted on and .serving to'fclose the ends of theV sleeves and hav#Y ing continuous 1 side'Y 'walls with. bar receiving notches therein in Y"registry iwith thenotchesfin the -outer' extremities' of 1thesleeves',fandj dowel rods mounted slii'lably4 in thev'fsleevesjand 'extend-A ing across 'the centrall 'portions thereof.

' 4. In a j oir'it-gfi-)rv contiguous concrete the combinationfof apair oflaterallyspaced'lad distributing bars adapted l'for' em'be'dment in and to "extend transversely jthrough thev slabs ref spectively,l 'a i plurality of one-piece v sleeves between the bars/adapted tof-haveV the-end portions.

y.thereof bonded'respective]y'tov the slabs and hav'.

ing their extreme outer ends connected` to the l "bars and the. central vportionsthereof 'weakened` i to Ysuch an extent thalt'they will' readily expander distendor rupture, and hence Ypermit 'entr-portions'to move -to .and fromone anotherin 'response to expansion andjcontraction'of the slabs, dowel rods mounted' lsli'clably'in the sleeves andextend'ff ing Vacross the central portions thereof, and

lindividual shields extending around :the "central weakenedportions ofthe-sleeves and each conf sisting of a pairA of complemental `telesco'ping and ring-shaped sections.

v 55'. In combination,y a'p'a'irofdjoining 'concrete-,- slabs withfafsubstantiallyfsolid filler-sof elastic material therebetween, a pair ofg laterally spacedloa d"distributing' bars embedded in vand f extending -ttran'sversely vthrough the "adjoiningV slabsy respectively, a plurality of metallici,one-y piece' 1 sleeves 'extending' between `the bars Vand kthrough theslabs andthe filler and having their extreme outer ends connected to the barsand the central portions thereofwveakened to's'uch an extent vthat A,they-will readily expand' or Vdistend or rupture/and hence permitsaidjend portions .-to 'moveto and from oneanother in responseto expansion and contraction of the slabs,and dowel Arods mountedslidablyin vthe sleeves 'and extend-fv I vving across thecentral portions thereof.

6. In combination, a 'pair offadjoining l,conf

crete slabs with a resilient finer therebetween; a .pair of `Alaterally`r spaced load` distributing bars embedded infandextendingftransversely through the adjoining slabsy respectively, ai pl'uralityIofi4 metallic vone piece sleeves `extending between the" bars and through the slabs and thefille'r and havA ing their .extreme outerfe'ndszconnected kt 'the barsand the .central portionsV thereof weakened .l tosuch an extent that they will readilyexpand otherfin response to contraction of the slabs,V

ordistend or' lruptureand hence permit said end portionsto move lt'oandffrom'one anotherin-:re-

spouse to expansion andec'ontraction offtheslabs,

'dowel rods-'mounted slidably inthe sleeves and extending'centrallyfacross the central portionsY thereotand individual annular shields embeddedr` inthe filler'Y and extending around the weakened centralportions'ofthe sleeves. i '7. In a. contraction joint for'contiguous 'con-' crete'slabs, the combinationof a pair of laterally spaced load distributing bars adapted for ernbedment in a'nd'ftol extend" transversely through then slabs respectively-a plurality offmetallic one-y piece sleeves between-the .bars adapted to .have the yend portionsl thereof' bondedY respectively' to .theslabsand havin'gthelr' extreme outer endsv connectedY to thel-barsfand the central portions thereofl slittedand .bulged outwards sc 'as to perinitthe` end portions .to move away from one an- Vthe slabsv lrespectively,4r aplurality of "metallid one-piece f sleeves between`A thel bars 'adapted to have the Vend portions thereof bonded respectively N and Vdowel rodsl mountedfjslidably in the sleeves and extending across the central portions thereof. y

In'combination, a pair ofadjoinin'gconcrete slabs, afseries of vlaterally spaced substantially Cily parallelfone piece'metallic sleeves fex't'endir'ig between and through theslab's and having the end i portions thereof nondedito the nabsrespecuvely and having the portions thereofbetweenthe siabs weakened to such an jexte'nt that theynvvilll readily expander distend or yrupture andfhence'. permit`` said end portions Yto movetandfrom one' an` other in response ,to expansion and contraction of the slabs, dowel rodsmountedfslidably inithe l j I.

sleeves 'and extending acrosstheweakened pon-" tions thereof, and individual expansibleand convtr'actible annular shields' around V'salmi weakened n portionsof' the sleeves.A

j 9. In a joint for contiguo v y combination of a pair/oi.' laterallyfspaced Ql'oagi concretas-labs, f 20 distributing barsadaptedfor embedment in and to :extend transverselythrough thefslebs 'respfecfg and adapted to cfr'oss the space between said slabs;

the dowel rodsand'h'aving ntcheslmtheirouter! extremitiesthrough which the bars extend, and

separately formed capsmounted` o n Vand servingto clo'seisaid outer extremities of lthe sleevememfA side -walls with bar "receiving notchesithe'rein in registry with the notchesin thesleevelmembe'rs;

combination of a` pair of :laterally spaced load the` bars andV adapted lto cross'the space vbetWeen tively, a series oflaterally?spaced'l substantially e' parallel dowel rodsextending between .the liars.`

-sleeve members slidablymountedon the endsofff bers vand 'embodying "[substantiallyl continuous the'ends ofthe dowel rods'and having pairs of opposed notches with kilaredv entrances in their tend' and' into Vwmcirthe barsv arejadaptedtc bef inserted by lateral. movement .th'eredf in"''0'nn' 'outer extremities, through which the-,b ars'gex" tion with assemblyof the joint; and yseparfat'elyiv'YV formed caps mounted on andservingto close said outerextremitiesof the-sleeve members and em. i i

so y. .y

bodying substantiallycontinuous side walls 'with" l pairs' of opposed notches 1 therein {disposed-in'.

. registry with 4'the notches. inthe 'sleeve members'- and having -flared entrancesior.; facilitating `mounting into their operative position with rey y' spect to said sleeve'membersaridbars.r V11 In acontraction joint for contiguousjion crete: slabs, 'the combination of "a 'pair of y laterally spaced f load distributing-bars adapted 1 for Vein# bedment in and to extend transversely'throughA tothe slabsand having 'theirextreme outer rends connected to the'bars andthe central portions thereof slitted'and hulgedoutwardsl so as t0 per-" 4mit the end portions tomove away froinvone anvother in response toggcontraction of. the ,slabs,`'

dowelrods "mounted slidably in the'sleeves and.,

extending" across 'the central y'portions thereof, A

and individualy shieldsl 'extending around the' centrall portions of the( sleevesj-and serving ton prevent "concrete from flowing" into .the sleeves via the slits'du'ringA formation ofthe slabs.

f 1 v i ERNEST H. GEYER'.; 

